Harley Quinn certainly can't be accused of pulling its punches. Season 4, Episode 7, "The Most Culturally Impactful Film Franchise of All Time," announces its target right off the bat. It may feel a little cryptic, especially since the episode itself involves time travel to a dystopic future Gotham City, but the episode doesn't waste time with the explanation. It's a dig at Avatar, James Cameron's staggeringly-popular-yet-weirdly-inert sci-fi franchise. The joke is spot-on not only for the way it skewers its target but also because, frankly, Cameron started it.
Source：https://www.cbr.com/harley-quinn-avatar-jab-right/
